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Discussion Starter · #1 · (Edited)
There are two small vacuum hoses coming from the throttle body. if your looking down at it the top one goes to the BCV located on the back wall and the other (the one that is a real PITA) goes back and has a check valve inline and connects to the hose going into the valve cover. I keep having the second hose that goes back to the valve cover coming off the throttle body. Check valve works fine and the other end stays on the end attaching to the valve cover, but the part that plugs into the TB keeps coming off. Anyone know what would cause this?
 

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There are two small vacuum hoses coming from the throttle body. if your looking down at it the top one goes to the BCV located on the back wall and the other (the one that is a real PITA) goes back and has a check valve inline and connects to the hose going into the valve cover. I keep having the second hose that goes back to the valve cover coming off the throttle body. Check valve works fine and the other end stays on the end attaching to the valve cover, but the part that plugs into the TB keeps coming off. Anyone know what would cause this?
It could be that the hose is getting old and doesn't fit as snug as it use to. On my NG900 the same line kept popping off but on the valve cover side. After I replaced the hose it hasen't popped off since.
 

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Discussion Starter · #4 ·
Maybe a small tie-wrap would keep it on... Ron

Have u seen the space in there? My big *** hands literally just cant fit. I could tiewrap it, but that's a pain really. I was just curious if anyone had some insight on maybe why its doing it. It is actually a new hose.

I was just wondering if maybe was a vent problem, but venting that way, that would mean it is venting the valve cover too much and blowing it off? Would I be correct there?
 

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How tight of a fit is the hose? If you replaced the hose with one based on the diameter of the check valve it may be too loose on the TB fitting which is smaller.
 

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it pops off because the throttle body becomes pressurized when you get into boost. the check valve is to prevent boost pressure from entering the crank case, and must be positioned correctly
 

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Discussion Starter · #7 ·
it pops off because the throttle body becomes pressurized when you get into boost. the check valve is to prevent boost pressure from entering the crank case, and must be positioned correctly

Seeing there is no schematic/manual or anything saying how it should be positioned, does anyone know of the proper positioning or how this thing should sit? THere arnt really too many options?? It just kinda sits on top the other hoses because it has to come up to connect back into the tube into the crank case.
 

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Positioned as in the check must stop flow in the correct direction. It should be marked but if not the nipple that you can blow through should have the hose attached that goes to the valve cover. The side you cannot blow through should have the hose that goes to the TB. If you can.blow through both sides the valve is bad. If you can't blow.through either the valve is bad.

Sent from my DROIDX using AutoGuide.Com Free App
 

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Discussion Starter · #9 ·
Positioned as in the check must stop flow in the correct direction. It should be marked but if not the nipple that you can blow through should have the hose attached that goes to the valve cover. The side you cannot blow through should have the hose that goes to the TB. If you can.blow through both sides the valve is bad. If you can't blow.through either the valve is bad.



Sent from my DROIDX using AutoGuide.Com Free App
No I can blow through the side coming from the valve cover to the TB. I cant blow back from it. But, just how much back pressure is coming back form the TB? Its the same size hose as all the others... I just cant figure out why its blowing off the TB side.
 

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If it's the smaller diameter hose from the valve cover to throttle body, just replace it. MAKE SURE the replacement hose is OIL RESISTANT or it'll have issues. Get a hose with a stiff wall so it won't soften in a week. Sounds like your hose is just old and/or has oil coating it so it's not staying put anymore. To reapply, use long needle nose pliers.

Can get a section of hose for like a $1 a foot at Auto Zone or wherever. Take your old one in and ask them to match it, and say it needs to be oil resistant. BE VERY careful with the plastic nipple on the "T" off at the valve cover as well as the check valve as they break easily. If a hose is stuck, score it length-wise with a razor very carefully. Not easy to get replacements for the "T". You can get a universal check valve though if needed.
 

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he already specified that the hose is new. if you are running a factory tune should be about 10psi +-1-2psi. I use small zip ties to hold the hoses on.
 

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Discussion Starter · #13 ·
he already specified that the hose is new. if you are running a factory tune should be about 10psi +-1-2psi. I use small zip ties to hold the hoses on.

Yes I did. The hose is new, and correct same size as any of the hoses. Its not factory, probably a very mild stage2 tune. I guess I will have to just zip tie it. I was just curious why it just all of a sudden started doing it.
 
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